Craig Halkett’s first-half red card proved costly for William Hill Premiership leaders Hearts as they went down 1-0 away to St Mirren following a late header from Miguel Freckleton.
The centre-back was dismissed in the 29th minute for denying Saints’ debutant Jacob Devaney a goalscoring opportunity.
It was the third time in five league games the Jambos had been reduced to 10 men. Unlike the previous two occasions, however, they were unable to grind out a result in Paisley as Freckleton’s 88th-minute header consigned them to a third defeat of the season.
The result leaves Hearts six points ahead of Celtic and Rangers, both of whom play their games in hand on Wednesday.
Hearts suffered a huge blow in the 29th minute when they were reduced to 10 men. Stuart Findlay got caught dithering on the ball by Mikael Mandron, forcing fellow centre-back Halkett into some frantic last-ditch defending that resulted in him fouling Devaney just outside the box and being sent off.
Devaney, an on-loan Manchester United midfielder who has five caps for the Republic of Ireland U21s and was one of two Irish players in the St Mirren line-up alongside Killian Phillips.
From the resulting free-kick, Phillips’ effort was superbly saved by Schwolow, with Mandron unable to force in the rebound.
There was more frustration for the hosts just before half-time when they were awarded a penalty after Harry Milne fouled Jayden Richardson on the right edge of the box, but VAR deemed the offence was outside the box. John fizzed the resulting free-kick agonisingly beyond the far post.
Saints continued to knock on the door early in the second half and Schwolow produced a spectacular save to deny Mandron.
But Hearts started to become a threat on the counter-attack, with Claudio Braga in particular carrying the fight to the Saints defence.
It felt like the game could go either way in the closing stages, and Saints eventually made the breakthrough when Freckleton headed home John’s corner from close range.